NIMCET 2013 Question Paper with solutions

© examsiri.com

Question : 23 of 120

Marks: +1, -0

Force

3i↖{→}+2j↖{→}+5k↖{→}

and

2i↖{→}+j↖{→}-3k↖{→}

are acting ona particle and displace it from the point

2i↖{→}-j↖{→}-3k↖{→}

to the point

4i↖{→}-3j↖{→}+7k↖{→}

, then the work done by the force is:

18 units
30 units
24 units
36 units

Solution:

Work done = Force × Displacement

=(5i↖{⋀}+3j↖{⋀}+2k↖{⋀})×(2i↖{⋀}-2j↖{⋀}+10k↖{⋀})

[∵ force

=5i↖{⋀}+3j↖{⋀}+2k↖{⋀}

] and displacement

=2i↖{⋀}-2j↖{⋀}+10k↖{⋀}

=10-6+20=24

© examsiri.com

Go to Question:

Prev Question

Next Question